Should secretion be excessive, astringents are indicated; and choice may be made from alum, five grains to the ounce of rose-water; tannic acid, two or three grains; zinc sulphate or zinc sulphocarbolate, two grains; lead acetate, two grains; ferric chloride, one grain; and silver nitrate, half a grain to the ounce. Personal supervision of the initial inhalations is requisite to ensure proper use of the spray. Whether the medicament is to be propelled directly into the larynx by means of a tube with a vertical tip to be passed beyond the tongue, or to be inhaled by efforts of inspiration from spray projected horizontally, will depend upon the skill of the individual using it. Hard-rubber {126} spray-producers are furnished with series of tips, so that either method may be employed. When the horizontal tip is used, the instrument should be held some distance from the mouth, so that the spray may be deflected into the larynx by the act of inspiration. When the tube is placed within the mouth most of the spray becomes condensed upon the pharynx, and very little can be drawn down into the larynx. As metallic tubes are liable to become reduced by certain remedies--ammonium chloride, for instance--tubes of glass or of hard rubber are to be preferred. Should a steam apparatus be employed, the patient should remain housed for half an hour after inhalation, except in very warm weather. In cases of hyperæsthetic mucous membrane the home inhalation of volatile remedies daily is often useful. Compound tincture of benzoin, camphorated tincture of opium, oil of pine, oil of turpentine, terebene, eucalyptol, creasote, carbolic acid, may be inhaled from a bottle containing hot water or from a special inhaler, a few drops of chloroform being advantageously added when there is a good deal of irritative cough. A few drops of the more pungent volatile substances, such as terebene, eucalyptol, and creasote, may be dropped on the sponge supplied with the perforated zinc respirator of Yeo of London, and the apparatus be worn for an hour or longer continuously. In cases with excessive secretion and in syphilis, ethyl iodide is indicated as a remedy appropriately administered by this method. When the parts are very irritable, a respirator of this kind or some similar contrivance, or a fold or two of woollen or silk gauze worn in front of the mouth and nose while in the open air, will often protect the tissues from too cool an atmosphere, and enable the patient to bear exposure with comfort.